Turbocharger housing

ABSTRACT

A turbocharger housing is split lengthwise and has two housing halves, which in the assembled state sectionally form a bearing housing, a turbine housing, and a compressor housing. The turbocharger housing contains at least one fluid chamber, which is arranged in the bearing housing and/or in the turbine housing and/or in the compressor housing of at least one of the two housing halves. The fluid chamber contains a plurality of raised webs, which are disposed to influence the fluid flow.

The present invention relates to a turbocharger housing, wherein theturbocharger housing comprises a compressor housing and a turbinehousing, together with a bearing housing.

Turbochargers generally serve to improve the efficiency of an internalcombustion engine and thereby to boost its power output. For thispurpose the turbocharger comprises a turbine with a turbine rotor and acompressor with a compressor wheel, the two rotors being arranged on acommon rotor shaft. Here the turbine rotor is driven via an exhaust gasmass flow of a connected internal combustion engine and in turn drivesthe compressor wheel. Here the compressor compresses the aspirated airand delivers this to the internal combustion engine. The rotor shaft issupported here in a bearing housing of the turbocharger. The turbinerotor of the turbine is furthermore arranged in a turbine housing andthe compressor wheel of the compressor is arranged in a compressorhousing. The bearing housing, the turbine housing and the compressorhousing together form the turbocharger housing. The turbine rotor, thecompressor wheel and the rotor shaft together form the rotor runner.

In operation on the internal combustion engine or a connected engine,such a turbocharger has to fulfill diverse requirements. One of theserequirements is to absorb the high temperatures occurring, which can begenerated in the turbocharger housing due to the hot exhaust gas massflow.

The usual design of the turbocharger here provides for individualhousings, each of a material matched to the temperature prevailingthere.

Here the compressor housing is usually made of aluminum, whilst thebearing housing is made of grey cast iron and may additionally be ofwater-cooled construction. The turbine housing is in turn generally madefrom materials having a high nickel content, owing to the hightemperatures that prevail in this area. Because of the various materialsmatched to the individual housings, these housings are formed asseparate parts, which have to be connected together and at the same timesealed off from one another. Such a turbocharger is therefore costly tomanufacture and assemble.

A turbocharger housing which avoids the aforementioned disadvantages isdisclosed, for example, in German patent application 10 2009 053 106.8.In this case the turbocharger housing is designed at least partially orcompletely divided into at least two parts in a longitudinal direction,that is to say in the longitudinal direction of the rotor shaft, theportion of the turbocharger housing divided in a longitudinal directionin each case comprising a part of the compressor housing, a part of thebearing housing and/or a part of the turbine housing. Here theturbocharger housing may be manufactured from aluminum, for example, oran aluminum alloy or another metal or metal alloy, or another suitablematerial.

The division in a longitudinal direction, in the present examplereferred to as a horizontal or substantially horizontal division,firstly affords direct advantages. For example an automated pre-assemblyof the rotor runner, including the two rotors, such as the compressorwheel and the turbine rotor, and the rotor shaft, is possible. This alsoclearly facilitates subsequent fitting in the turbocharger.

In addition, provision is made for an additional temperature control,for example cooling and/or heating, of at least a part of theturbocharger housing, for example the turbine housing, the bearinghousing and/or the compressor housing. For this purpose a fluid ortemperature control jacket having a fluid core is provided. As shown inFIG. 1, for example, this fluid jacket spans the bearing housing portionand the turbine housing portion of the turbocharger housing. A coolingmedium flows through the fluid or temperature control jacket having afluid core, also referred to as a fluid chamber. This additionallyaffords cooling of the turbine housing and the bearing housing.

The turbocharger housing here has the advantage that the rotor runner,that is to say the rotors on the rotor shaft and the bearing arrangementof the rotor shaft, can be pre-assembled and then inserted complete intothe housing halves. In addition, the rotor runner can be subjected tooperational balancing beforehand, without previously having to fit it inthe turbocharger housing.

The fluid chambers incorporated into a turbocharger housing are oftenvery flat, however, in order to save weight and overall space. The flowbehavior of the cooling medium thereby certainly often suffers,resulting in irregular flows through the fluid chamber and hence unevencooling. In extreme cases it can happen that a part of the turbochargerhousing to be cooled is poorly cooled, if at all, during operation ofthe turbocharger.

The object of the present invention is to provide an improvedturbocharger housing, which does not have the aforementioneddisadvantages.

This object is achieved in a turbocharger housing of generic type havingthe characterizing features of claim 1.

In this turbocharger housing at least one portion, formed from a turbinehousing, a bearing housing and/or a compressor housing, is divided in alongitudinal direction into two housing halves, which in the assembledstate in portions form a bearing housing, a turbine housing and acompressor housing. Here at least one fluid chamber, which in operationis charged with a cooling medium, is arranged in the bearing housingand/or in the turbine housing and/or in the compressor housing of atleast one of the two housing halves. The fluid chamber here ischaracterized in that it comprises a plurality of raised webs, which actas restrictions for the cooling medium, so that the cooling medium formsflows, which run in various directions. This serves to prevent isolatedareas of the turbocharger being insufficiently cooled or even not cooledat all.

Advantageous embodiments and developments of the invention arecharacterized in the dependent claims and the subsequent description ofthe figures.

The invention is explained in more detail below with reference to thedrawing, in which:

FIG. 1 shows a sectional view of a housing half of a turbochargerhousing, augmented by the raised webs provided according to theinvention;

FIG. 2 shows a top view of a housing half (detail FIG. 2A), in lateralsection (detail FIG. 2B) and in cross section (detail FIG. 2C);

FIG. 3 shows an outer part of a turbine housing as part of aturbocharger housing;

FIG. 4 shows a side view of the outer part according to FIG. 3;

FIG. 5 shows a gasket for assembly of the two housing halves of theturbocharger housing according to the invention.

Unless otherwise stated, the same or functionally equivalent elementsand devices have been provided with the same reference numerals in allfigures. The representation of the turbocharger shown in the followingfigures is moreover purely schematic, not to scale and highlysimplified.

FIG. 1 is a sectional view through a housing half 10 of a turbochargerhousing 12 according to a first embodiment of the invention, the housinghalf 10 here being shown from the gasket side. In FIG. 1 a recess 50 orgroove for receiving a sealing device is shown as an example.

In this example the turbocharger housing 12 here comprises a bearinghousing 14, a turbine housing 16 and a compressor housing 18, all threehousings being united to form one housing 12. In the case shown, a partof the invention resides in the initial notion of uniting all threehousings, 14, 16, 18, for example, and producing these as one part, forexample from an integral casting. For assembling the rotor runner andfor machining the inner working faces, a division is furthermoredefined, through which the interior of the housing 12 can be opened up.According to the invention this division is made in a longitudinaldirection, that is to say in the direction of the axis of the rotorshaft, the plane of division lying in one or more planes in which therotor shaft 26 lies, or which are arranged substantially parallel to therotor shaft 26. Here the rotational position of the plane of divisionabout the axis of the rotor shaft may be selected, as required, at anangle of between 0° and 360°. In principle the entire turbochargerhousing 12, comprising the compressor housing 18, the turbine housing 16and the bearing housing 14, may be of longitudinally divided design. Itis also possible, however, to design just one portion of theturbocharger housing 12 with a longitudinal division, the portioncomprising a rotor housing 16, 18 and/or the bearing housing 14.

As shown in FIG. 1, the turbine housing 16, the bearing housing 14 andthe compressor housing 18 may be formed from two housing halves 10 eachin one piece. In this case in FIG. 1 the turbocharger housing 12 isdivided into two housing halves 10 in a continuous plane, in which theaxis of the rotor shaft 26 lies. Here a first housing half 10,comprising the turbine housing 16, the bearing housing 14 and thecompressor housing 18, for example, forms the so-called upper part, anda second housing half, comprising the turbine housing 16, the bearinghousing 14 and the compressor housing 18, forms the so-called lowerpart. FIG. 1 here shows a housing half 10 from the gasket side. Herethis housing half 10 is fastened, for example bolted, to the otherhousing half (not shown). For this purpose, in the embodiment shown inFIG. 1, multiple bores 20, in this case six bores, for example, areprovided for bolting the two housing halves together. In principle,however, any other form of fastening the housing halves may also beprovided.

The division in a longitudinal direction firstly affords directadvantages. For example, an automated pre-assembly of the rotor runner,including the two rotors, such as the compressor wheel 22 and theturbine rotor 24, and the shaft 26, is possible. This also clearlyfacilitates subsequent fitting in the turbocharger. In addition, ifprovision is made for an additional temperature control, for examplecooling and/or heating, of at least a part of the turbocharger housing12, for example the turbine housing 16, the bearing housing 14 and/orthe compressor housing 12, a fluid or temperature control jacket 28having a fluid core may be provided. In the example in FIG. 1 this fluidjacket 28, for example, spans the bearing housing portion 14 and theturbine housing portion 16 of the turbocharger housing 12 without anyback taper, since in this example the turbine housing 16 and the bearinghousing 14 are to be additionally cooled, for example. This means, forexample, that a sand core for producing the fluid jacket 28 does nothave to be assembled and bonded together from several pieces.

A further advantage is that at least one half or the overallturbocharger housing 12 can be integrated into the engine block and/orthe cylinder head of a connected engine. In this case, for example, thelower part of the turbocharger housing 12 can be integrated into theengine block and the upper part into the cylinder head, or vice versa.

In FIG. 1 the shaft 26, on which the turbine rotor 24 and the compressorwheel 22 are provided, is supported in the bearing housing portion 14 ofthe turbocharger housing 12. The turbine rotor 24 here is arranged inthe turbine housing portion 16 and the compressor wheel 22 in thecompressor housing portion 18. The shaft 26 furthermore comprises aradial bearing arrangement 30 and optionally also an axial bearingarrangement 32.

In the turbocharger according to the invention, which through thedivision forms two bore halves, for example, the bearing arrangement 30is fitted, axially braced, for example by way of sprung collar portions34.

In FIG. 1 the shaft 26 is supported via the radial bearing arrangement30 and the axial bearing arrangement 32. The radial bearing arrangement30 here comprises a through-sleeve 36, which at each of its two endsforms a slide bearing portion 38 for supporting the shaft 26 in a radialdirection. Here the sleeve 36 is pushed on to the shaft 36, the shaft 26forming a step with a stop for the sleeve 36. At the other end of thesleeve 36 an axial bearing arrangement 32 is provided, the axial bearingarrangement 32 comprising at least one axial bearing in the form of anaxial bearing disk 40. In addition an oil baffle plate 42 is arranged onthe axial bearing disk 40 here. Furthermore a layer 44 composed of atleast one or more coatings of heat-resistant or temperature-resistant,elastic material, such as a polymer, an elastomer and/or a hard rubber,for example, is additionally arranged on the outside of the sleeve 36.

A sleeve element 46 is also provided on the outside of the layer 44 ofthe elastic, temperature-resistant material. The sleeve element 46 hereis made, for example, of metal, for example steel. Alternatively theelastic, temperature-resistant material may also be dispensed with andinstead the sleeve element 46 may be provided directly on the outside ofthe sleeve 36 (not shown), or the sleeve 36 may optionally be designedso that it functions not only as a radial bearing arrangement 30 butalso as a sleeve element 46 (not shown).

In the example shown in FIG. 1 the sleeve element 46 comprises a collarportion 34 at each of its two ends. Here at least one or both of thecollar portions 34 of the sleeve element 46 is of sprung design,allowing it to be clamped between two stops or mounts 48 of theturbocharger housing 12. On or both collar portions 34 may equally wellbe unsprung, that is to say of rigid design and inserted between the twomounts 48, or alternatively they may also be screw-fastened to themounts 48 on one or both sides. Alternatively at least one of the sprungcollar portions 34 may likewise be additionally fastened to therespective mount 48, for example by bolting. Here one or both collarportions 34 may be integrally connected to the sleeve element 46 orfastened thereto as a separate part (not shown). The bearing arrangement30, in this case the radial bearing arrangement 30, comprising thesleeve 36 and the elastic layer 44, is axially fixed or braced in theturbocharger housing 12, that is to say the two housing halves 10 of theturbocharger housing 12 via the two collar portions 34 of the sleeveelement 46.

Here at least one collar portion 34 may also additionally be led out ofthe oil chamber, as in FIG. 1 on the turbine side, and may assumefurther functions as a heat shield. One or both collar portions 34,however, may also remain inside the oil chamber, such as the collarportion 34 of the sleeve element 46 on the compressor side. In additionsuch a bearing arrangement 30 has the advantage that it can bepreassembled in its entirety and can therefore be operationally balancedwithout the enclosing housing, for example.

The radial bearing arrangement 30 and the axial bearing arrangement 32in FIG. 1 are merely one example of a bearing of the shaft 26 in aradial and an axial direction. In principle the shaft 26 in theturbocharger housing 12 according to the invention may comprise anyother radial bearing arrangement and/or axial bearing arrangement. Thusthe sleeve 36, for example, may also be replaced by two radial slidebearings (not shown), the two slide bearings, for example, alternativelyin addition comprising a spacer sleeve, or the sleeve element 46 on itsinner side comprising a mount for one or each of the two slide bearings(not shown). Besides slide bearings, non-contact bearings such asmagnetic bearings and rolling bearings, for example, may also beprovided for radial and/or axial support. The invention is not confinedto the examples of bearing arrangements shown and described.

In the fluid chamber 28 represented in FIG. 1, two raised webs 6,provided according to the invention, are drawn in, which have alongitudinal extent in the axial direction of the rotor shaft. Theraised webs 6 drawn in FIG. 1 have a height H, which extends from oneedge of the fluid chamber 28 to the edge of the fluid chamber 28situated opposite this edge and which therefore corresponds to theheight of the fluid chamber 28 at this point.

FIG. 2 in its first detail drawing 2A shows a top view of one of thehousing parts 10 and 11 with a fluid chamber 28 and a plurality ofraised webs 6 arranged therein. When the fluid chamber 28 is beingcharged with a cooling medium (in the operation of a ready fittedturbocharger having the turbocharger housing according to theinvention), the raised webs 6 act as restrictions for the coolingmedium; accordingly turbulences and flows running in various directionsform in the cooling medium. This is precisely what is intended accordingto the invention, since it serves to prevent isolated areas of theturbocharger being insufficiently cooled or even not cooled at all. Suchdeficiencies would in fact result in premature damage to theturbocharger, or they would at least adversely affect its service lifein the long term.

The detail FIG. 2B shows the housing half in detail FIG. 2A in a lateralsection along the section line A-A in detail FIG. 2A. Here too, theraised webs 6 can again be seen. The detail FIG. 2C shows the housinghalf represented in the detail FIG. 2A in cross section along thesection line B-B in FIG. 2A. It is also shown here that the raised webs6 need not necessarily have the height H previously described, whichextends from one edge of the fluid chamber 28 to the edge situatedopposite this edge, but that the raised webs 6 may also be of a lesserheight. This is clearly indicated by the reference symbol H′ in thedetail FIG. 2C. The detail FIG. 2A also shows two connection points A,via which in operation the cooling medium can be delivered to and ledoff from the turbocharger again.

FIG. 3 representing an outer part of the turbine housing 16 of aturbocharger with the two housing parts 10 and 11 (at least partiallyrepresented) shows a possible positioning of the raised webs 6 and theresulting flow behavior of the cooling medium illustrated by arrows.Also shown is one of the connections A already mentioned.

FIG. 4 in a side view shows the outer part represented in FIG. 3together with some of the raised webs 6 and the connections A.

FIG. 5 shows a gasket 4 of the type that may be used in assembling thetwo housing halves 10 and 11 of an inventive turbocharger housing of aturbocharger. Besides various other openings of no interest here, thegasket 4 has a number of cutouts 4 a, for example in the form of boresor punched holes, in the area in which it separates the fluid chambers28 of the two housing halves 10 and 11 from one another. As the coolingmedium is thereby allowed to pass from one housing part 10 or 11 intothe other housing part 11 or 10, turbulences of the cooling medium occurat the cutouts 4 a, which then also, as already described with regard tothe raised webs 6, promote a uniform cooling of the components to becooled.

1-6. (canceled)
 7. A turbocharger housing, comprising: at least oneportion being divided in a longitudinal direction into two housinghalves, said two housing halves in an assembled state in portions form abearing housing, a turbine housing and a compressor housing; and atleast one fluid chamber for receiving a cooling medium and disposed inat least one of said bearing housing, said turbine housing or saidcompressor housing of at least one of said two housing halves, saidfluid chamber having a plurality of raised webs, for forming flows ofthe cooling medium running in various directions.
 8. The turbochargerhousing according to claim 7, wherein at least one of said raised webshas a height being equal to a height of said fluid chamber at a pointwhere said one raised web is situated.
 9. The turbocharger housingaccording to claim 7, wherein at least one of said raised webs has aheight being less than a height of said fluid chamber at a point wheresaid one raised web is situated.
 10. The turbocharger housing accordingto claim 7, further comprising connections, via said connections thecooling medium can be delivered to and led off from said fluid chamber.11. The turbocharger housing according to claim 7, further comprising agasket disposed between said two housing halves, said gasket in an areawhere said fluid chamber extends over both of said two housing halveshas at least one cutout formed therein, via which the cooling medium isable to flow from a first of said two housing halves into a second ofsaid two housing halves.
 12. The turbocharger housing according to claim11, wherein said cutout is one of a plurality of cutouts formed in saidgasket.
 13. The turbocharger housing according to claim 12, wherein saidcutouts have are selected from the group consisting of bore holes andpunched holes.